Apparatus for automatically regulating the draft in boiler-furnaces.



G. DE GRAHL. APPARATUS FOR AUTOMATICALLY REGULATING'THE DRAFT IN BOILER FURNACES.

APPLICATION FILED JAN. 6, 1912.

1,079,853. Patented Nov. 25, 1913.

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COLUMBIA PLANOGRAPII co., WASHINGTON. n c.

e. DE GRAHL. APPARATUS FOR AUTOMATICALLY REGULATING THE DRAFT IN BOILER FURNACES.

APPLICATION FILED JAN. 6. 1912.

Patented Nov. 25, 1913.

2 sums-slum 2.

GUSTAV DE GRAHL, or ZEI-ILENDOBIE, NEAR BERLIN, GERMANY.

APPARATUS FOR AUTOMATICALLY REGULATIITG THE DRAFT IN BOILER-FURNACES.

Specification of Letters Patent.

Application filed January 6, 1912. Serial No. 669,828

T 0 all whom it may concern Be it known that I, GUSTAV DE GRAHL, a subject of the German Emperor, and residing at Zehlendorf, near Berlin, Germany, have invented certain new and useful 1111-. provements in Apparatus for Automatically Regulating the Draft in Boiler-Furnaces, of which the following is a specification.

The subject-matter of my invention is a device for the fire-doors of boiler-furnaces for regulating the admission of auxiliary air into the firebox.

My device substantially consists in the fire-door being provided with two superposed air-conduits for automatically admitting air into the fire-box. In these conduits I arrange flaps or valves whose maximum stroke can be adjusted independently of one another, so that air can be admitted at various elevations from without into the firebox and the maximum quantity of the same can be regulated according to the adjustment of the stroke.

One illustrative embodiment of my invention is represented by way of example in the accompanying drawings, wherein Figure 1 is a front elevation of a fire-door provided with my device. Fig. 2 is a vertical sect-ion through the same, and Figs. 31 and 4 show parts of the fire-door on an enlarged scale, Fig. 3 being a side elevation, partly in section, and Fig. 4 a cross-sectiom on line AB in Fig. 3.

Referring to the drawings, 1 designates the wall of the fire-box having the aperture 3 bounded by the ring 2 for the insertion of fuel. The plate 4 carrying the journal 5 for the vertical door-shaft 6 is mounted on the outer wall of the fire-box. The two strap-hinges 7, 8 are fast on the shaft 6 whose rotation is imparted to the door owing to the shoulder 10 of the sleeve 9 fast on the shaft coacting with a corresponding recess in the hinge 7. The rod 11 terminates at one end in the handle 12 and its other end is pivotally connected by the pivot 13 to the forked head 14 of the shaft.

In the closed position of the door shown 44 in each of the upper conduits 18, 18. The lower conduits are provided with heating ribs 21 and 21, and the upper conduits with similar ribs 22 and 22 Further, on one side wall of each pair of conduits is fixed a segment 45 connected by arms 46 with a sleeve 47. Each of the latter extends above the .adjacent appertaining valve through the lateral wall of the conduits, and carries a revoluble pivot 48 which carries on its end projecting into the air-conduit an arm 49 acting as a stop for the valve, and on the other end a lever 50. Each lever carries a handle 51 having a recess 52 (Fig. 4). The spring 53 in each recess 52 acts against the head 54 of the pointed pin 55 which is displaceably mounted in the handle 51 and provided with a nut 56.

Each of the segments 45 has a series of notches or holes 57 in which the pointed ends of the heads 54 can rest. The arms 49 are provided with springs 58 serving as resilient stops for the valves 19 and 20. The position of the arms 49 relatively to the valves 19, 20 is such that as soon as the heads 54 engage in the lowest holes 57 the arms 49 constituting the stops for the valves allow the valves to open a minimum amount just sufficient for cooling the door.

The shafts 23, 24 are j ournaled in the firedoor below the valves 19 and 20. The lever 25 is fast on the shaft 23 and the lever 26 is 1 fast on the shaft 24, and these two levers are connected together by a jointed rod in such manner that the motion of the shaft 23 is imparted to the shaft 24 and reversely. This ointed rod comprises the two parts 60, 61 of which the part 60 is pivotally connected with the lever 25 and the part 61 with the lever 26. The two parts 60, 61 are screw-threaded at their ends 62, 63 and screwed into the sleeve or nut 64. By rotating the nut 64 the rod 60, 61 can be lengthened or shortened as desired.

The levers 28, 28 are fast on the shaft 23 and the levers 29, 29 on the shaft 24. The lever 30 is fast on the shaft 23. The latter lever runs out into a pivot 31 carrying the anti-friction roller 32. The cataract-cylinder 35 is arranged under the shaft 6 with the axes in alinement. The piston 34 fast on the piston rod 33 is movable inthe .cataractcylinder. The piston-rod passing through the stuffing-box 41 carries at its upper end the plate 42 which, when the piston Patented Nov. 25,1913.

rises, acts against the roller 32. The pipe 36 opens above into the cylinder 35 which is connected below with the atmosphere.

37 designates a steam pipe provided with the valve 38. Between the pipes 36 and 37 is connected an injector comprising the easing 40and the nozzle 39.

The described apparatus operates as follows: As soon as a pressure below atmospheric occurs in the fire-box when the firedoor is shut, the valves 19, 20 are automati- 7 cally opened and admit air into the combus suction by means of the injector 39, 40. The

motion of the piston is then imparted to the lever and to the shaft 23 and through the medium of the jointed rod 60, 61 to the shaft 24. The shafts 23, 24 then act through their levers 28 and 29, respectively, on the valves 19, 20, respectively, and lift the same. The arrangement may be such that this piston 34 is automatically lifted by suction as soon as the main blast is shut down and the auxiliary blast operated, to which end the steam pipe 37 will be connected with the pipe leadingto the auxiliary blast.

If it is wished to transmit the motion of the cataract-piston only to the upper or only i to the lower valves, the jointed rod 60, 61

will be correspondingly altered in length by moving the nut 64. If the jointed rod be shortened by screwing the nut 64 clock-- wise (Fig. 3) when the piston 34 is lifted the valves 19 will open sooner than the valves 20, whereas, reversely, i. 6. when the rod is lengthened by turning the nut 64 counter -clockwise, the valves 20 will be opened earlier than thevalves 19.

I claim j 1. In apparatus for automatically regulating the draft in furnaces of locomotiveboilers the combination of a fire-box and a horizontally opening fire-door provided with air-conduits, arranged in pairs one over another opening below into the atmosphere and above into the fire-box, and means for admitting air in turns to difi'erent levels of the fire-box said means being controlled by the vacuum in the fire-box.

2. In apparatus for automatically regulating the draft in furnaces of locomotiveboilers the combination of a fire-box and. a

horizontally opening fire-door provided with air-conduits arranged in pairs one over the other opening below into the atmosphere and above into the fire-box, non-return flapvalves in said conduits, said valves being pivoted at one end and adapted to open automatically under the influence of the vacuum in the fire-box and stops positively connected with said valves for limiting th strokes of said valves, each of said stops being individually adjustable independent of each other.

3. In apparatus for automatically regulating the draft in furnaces of locomotiveboilers the combination of a fire-box and a horizontally opening fire-door provided with air-conduits, arranged in pairs one over another opening below into the atmosphere and above into the fire-box, non-return flapvalves in said conduits, said valves being pivoted at one end and adapted to open automatically under the influence of the draft in the fire-box; the individual flap-valves of each pair of conduits possessing difierent inclination toward the horizontal in their closed positions.

4. In apparatus for automatically regulating the draft in furnaces of locomotiveboilers the combination of a fire-box and a horizontally opening fire-door provided with air-conduits, arranged in pairs one over another opening below into the atmosphere and above into the fire-box non-return flapvalves in said conduits, said valves being pivoted at one end, and adapted to open automatically under the influence of the draft in the fire-box, the upper non-return flapvalves of each pair being downwardly inclined and the lower one of said pair horizontal in closed position.

5. In apparatus for automatically regulating the draft in furnaces of locomotiveboilers, the combination of a fire-box and a horizontally opening fire-door provided with air-conduits arranged in pairs one over another, openmg below into the atmosphere and above into the fire-box, non-return flapvalves in said conduits, said valves being pivoted at one end and adapted to open automatically under the influence of the draft in the fire-box, the individual fiap-valves of each pair of conduits possessing different inclination toward the horizontal in their closed position and adjustable stops positively connected with said valves for limiting the strokes of said flap-valves.

6. In apparatus for automatically regulating the draft in the furnaces of steam boilers, the combination of a fire-box, and a horizontally-opening fire-door provided with internally-ribbed air-conduits, arranged in pairs one over another, opening below into the atmosphere and above into the fire-box, and a non-return valve capable of opening automatically under the influence of the draft in the fire-box mounted in each airconduit; a shaft under the lower valves, a second shaft under the upper valves, means for imparting the movement of one shaft to the other, a cataract containing a piston, means for imparting the motion of said piston to one of said shafts, and arms fast on each of said shafts for opening the valves when the said shafts are rotated.

7. In apparatus for automatically regulating the draft in the furnaces of steam boilers, the combination of a fire-box, and a horizontally-opening fire-door provided with internally-ribbed air-conduits, arranged in pairs one over another, opening below into the atmosphere and above into the fire-box, and a non-return valve capable of opening automatically under the influence of the draft in the fire-box mounted in each airconduit; a shaft below the lower valves, a second shaft below the upper valves, a leverarm secured on each of the said shafts, a rod pivotally connected to the lever-ar1ns, a cataract containing a piston, means for imparting the motion of said piston to one of the two shafts, and arms fast on said shafts for opening said valves when the said piston is lifted.

8. In apparatus for automatically regulating the draft in the furnaces of steam boilers, the combination of a fire-box, and a horizontally-opening fire-door provided with internally-ribbed air-conduits, arranged in conduit; a shaft below the lower valves, a

second shaft below the upper valves, a leverarm secured on each of the said shafts, a rod of variable length pivotally connected to the lever-arms, a cataract containing a piston, means for imparting the motion of said piston to one of the two shafts, and arms fast on said shafts for opening said valves when the said piston is lifted.

In testimony whereof, I aflix my signature in the presence of two witnesses.

GUSTAV DE GRAHL. Witnesses:

HENRY HASPER, WOLDEMAR HAUPT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

